Spoilage and shelf-life extension of fresh fish and shellfish

The preservation effect of biodegradable gelatin coating incorporated with grape seed oil on glazed shrimp

BACKGROUND

This study was conducted to investigate the quality and shelf life of shrimps (Parapenaeus longirostris, Lucas 1846) glazed with biodegradable gelatin solutions combined with grape (Vitis vinifera L.) seed oil (GSO). Therefore, shrimps were divided into five groups and were glazed with distilled water (control), G (gelatin), G + 5% GSO (gelatin with 5% GSO), G + 10% GSO (gelatin with 10% GSO) and G + 15% GSO (gelatin with 15% GSO). Glazed shrimps were vacuum packaged and stored at -18 °C for 12 months. Proximate composition of the shrimps was determined, and the microbial (total viable counts, psychrotrophic bacteria count and Enterobacteriaceae), sensorial, chemical (residual sulfite, pH, total volatile basic nitrogen, trimethylamine nitrogen, thiobarbituric acid reactive substances) analysis, colour measurement, and melanosis formation were evaluated throughout the storage period.

RESULTS

According to the analysis results, edible G + GSO coatings improved the meat quality and the brightness of the shrimps. The combined treatment reduced the quality loss of the shrimps which was caused by lipid content and prevented the total psychotropic bacteria growth throughout the storage. Moreover, glazing with G + GSO retarded the melanosis formation of the frozen shrimps.

CONCLUSION

The study results revealed that GSO may be a recommended alternatively to sodium metabisulfite, which is a hazardous chemical substance commonly used against melanosis of shrimps. © 2023 Society of Chemical Industry.

Enhanced mechanical and functional properties of chitosan/polyvinyl alcohol/hydroxypropyl methylcellulose/alizarin composite film by incorporating cinnamon essential oil and tea polyphenols

In this study, cinnamon essential oil and tea polyphenols were added to chitosan/ polyvinyl alcohol/ hydroxypropyl methylcellulose/ alizarin composite films to enhance their mechanical and functional properties. Their addition to the composite films enhanced their antibacterial and antioxidant properties and significantly improved its elongation at break (p < 0.05). Cinnamon essential oil reduced the water vapor permeability, water content, and water solubility of composite films and improved their transparency. The composite films with additive exhibited excellent UV-barrier ability and pH responsivity. Fourier Transform infrared spectroscopy and X-Ray Diffraction analyses confirmed hydrogen bond formation between the polymer molecules and additives. The results of Scanning Electron Microscope-Focused Ion Beam revealed improved surface and cross-section morphology of the films, leading to the generation of a cross-linked structure. Thermogravimetric and differential scanning calorimetry analysis indicated enhanced thermal stability of the composite films upon cinnamon essential oil addition. Analysis of storage quality indicators (TBARS value, TVC, and TVB-N) revealed that the composite films could prolong the freshness of surimi. The incorporation of cinnamon essential oil and tea polyphenols into the composite films has demonstrated significant potential as an effective and natural alternative for active food packaging.

Effect of cinnamon essential oil dietary supplementation on the growth, fatty acid composition, and meat quality of tilapia

This study was conducted to investigate the effects of dietary supplementation of 0%, 0.2%, 0.35%, and 0.5% cinnamon essential oil on growth performance, fatty acid, and fillet quality of tilapia (Oreochromis niloticus). The results of growth experiments showed that the weight gain rate linearly and quadratically increased with increasing cinnamon essential oil doses (p < 0.05). The results of fatty acids experiments showed that the addition of essential oil significantly decreased the saturated fatty acids levels from 36.67% to 30.82% and increased the polyunsaturated fatty acids (PUFA) levels from 24.55% to 46.89%; especially, the n - 3 PUFA of 0.5% essential oil treatment showed the highest levels. Moreover, the n - 6 PUFA of 0.2% essential oil treatment were increased from 22.17% to 32.99%. The results of fillet quality experiments showed that the hardness and cohesiveness were linearly and quadratically increased with the increasing essential oil doses on days 4 and 7, respectively. The b* values linearly and quadratically decreased as the doses increased on day 7 (p < 0.05). The total volatile basic nitrogen levels were quadratically decreased with increasing cinnamon essential oil doses on day 7 (p < 0.05). In general, it can be concluded that cinnamon essential oil presented positive effects on the growth, nutritive values, and meat quality in tilapia.

Body yield and quality of fresh and post-freezing filet of Nile tilapia (Oreochromis niloticus) genetic groups

The aim of this study was to evaluate the body yield and quality of fresh and post-freezing filet of male and female fish of inbred and non-inbred AquaAmérica genetic group and the hybrid between the AquaAmérica and Tilamax varieties. Forty fish (20 males and 20 females) of each genetic group were housed in four 48-m3 hapa net cages, getting 120 fish per cage. The fish were housed at 51 days of age and farmed for 269 days. Pre-slaughter weight was higher (P<0.05) in the AquaAmérica × Tilamax males (0.805±0.204 kg) than in the inbred AquaAmérica male (0.643±0.115 kg). Filet yield percentage was higher (P<0.05) in the AquaAmérica × Tilamax males (32.14±4.72%) than in the inbred AquaAmérica (28.15±2.67%) and non-inbred AquaAmérica (29.06±2.80%) males. Head and viscera yield percentages, pH, color values (L*, a* and b*), shear force, drip loss and cooking loss did not differ significantly between the genetic groups and sexes. Alterations in meat quality were observed after freezing. In conclusion, inbreeding in the AquaAmérica variety resulted in reduced slaughter weight for males; AquaAmérica × Tilamax males have a higher filet yield; and filet quality is not influenced by crossing, inbreeding, or sex, but is changed after freezing.

Volatilome Analysis and Evolution in the Headspace of Packed Refrigerated Fish

Fresh fish is a perishable food in which chemical (namely oxidation) and microbiological degradation result in undesirable odor. Non-processed fish (i.e., raw fish) is increasingly commercialized in packaging systems which are convenient for its retailing and/or which can promote an extension of its shelf-life. Compared to fish sent to its retail unpackaged, fish packaging results in a modification of the gaseous composition of the atmosphere surrounding it. These modifications of atmosphere composition may affect both chemical and microbiological degradation pathways of fish constituents and thereby the volatile organic compounds produced. In addition to monitoring Total Volatile Basic Nitrogen (TVB-N), which is a common indicator to estimate non-processed fish freshness, analytical techniques such as gas chromatography coupled to mass spectrometry or techniques referred to as "electronic nose" allow either the identification of the entire set of these volatile compounds (the volatilome) and/or to selectively monitor some of them, respectively. Interestingly, monitoring these volatile organic compounds along fish storage might allow the identification of early-stage markers of fish alteration. In this context, to provide relevant information for the identification of volatile markers of non-processed packaged fish quality evolution during its storage, the following items have been successively reviewed: (1) inner atmosphere gaseous composition and evolution as a function of fish packaging systems; (2) fish constituents degradation pathways and analytical methods to monitor fish degradation with a focus on volatilome analysis; and (3) the effect of different factors affecting fish preservation (temperature, inner atmosphere composition, application of hurdle technology) on volatilome composition.

Characterization of the archaeal community in foods: The neglected part of the food microbiota

Despite the large number of studies conducted on archaea associated with extreme environments, the archaeal community composition in food products is still poorly known. Here, we investigated a new insight into exploring the archaeal community in several food matrices, with a particular focus on determining whether living archaea were present. A total of 71 samples of milk, cheese and its derived brine, honey, hamburger, clam, and trout were analyzed by high-throughput 16S rRNA sequencing. Archaea were detected in all the samples, ranging from 0.62 % of microbial communities in trout to 37.71 % in brine. Methanogens dominated 47.28 % of the archaeal communities, except for brine, which was dominated by halophilic taxa affiliated with the genus Haloquadratum (52.45 %). Clams were found to be a food with high richness and diversity of archaea and were targeted for culturing living archaea under different incubation time and temperature conditions. A subset of 16 communities derived from culture-dependent and culture-independent communities were assessed. Among the homogenates and living archaeal communities, the predominant taxa were distributed in the genera Nitrosopumilus (47.61 %) and Halorussus (78.78 %), respectively. A comparison of the 28 total taxa obtained by culture-dependent and culture-independent methods enabled their categorization into different groups, including detectable (8 out of 28), cultivable (8 out of 28), and detectable-cultivable (12 out of 28) taxa. Furthermore, using the culture method, the majority (14 out of 20) of living taxa grew at lower temperatures of 22 and 4 °C during long-term incubation, and few taxa (2 out of 20) were found at 37 °C during the initial days of incubation. Our results demonstrated the distribution of archaea in all analyzed food matrices, which opens new perspectives to expand our knowledge on archaea in foods and their beneficial and detrimental effects.

Chlorogenic Acid Inhibits Rahnella aquatilis KM25 Growth and Proteolytic Activity in Fish-Based Products

This work verified the antiproliferative and antiproteolytic activities of chlorogenic acid against Rahnella aquatilis KM25, a spoilage organism of raw salmon stored at 4 °C. Chlorogenic acid limited the growth of R. aqatilis KM25 in vitro at a concentration of 2.0 mg/mL. The dead (46%), viable (25%), and injured (20%) cell subpopulations were identified by flow cytometry following treatment of R. aquatilis KM25 with the examined agent. The exposure of R. aquatilis KM25 to chlorogenic acid altered its morphology. Changes in cell dimensions, mostly in length parameters from 0.778 µm to 1.09 µm, were found. The length of untreated cells ranged from 0.958 µm to 1.53 µm. The RT-qPCR experiments revealed changes in the expression of genes responsible for the proliferation and proteolytic activity of cells. Chlorogenic acid caused a significant reduction in the mRNA levels of the ftsZ, ftsA, ftsN, tolB, and M4 genes (-2.5, -1.5, -2.0, -1.5, and -1.5, respectively). In situ experiments confirmed the potential of chlorogenic acid to limit bacterial growth. A similar effect was noted in samples treated with benzoic acid, where the growth inhibition of R. aquatilis KM25 was 85-95%. Reduction of microbial R. aquatilis KM25 proliferation significantly limited total volatile base nitrogen (TVB-N) and trimethylamine (TMA-N) formation during storage, extending the shelf life of model products. The TVB-N and TMA-N parameters did not exceed the upper levels of the maximum permissible limit of acceptability. In this work, the TVB-N and TMA-N parameters were 10-25 mg/100 g and 2.5-20.5 mg/100 g, respectively; for samples with benzoic acid-supplemented marinades, the parameters TVB-N and TMA-N were 7.5-25.0 mg/100 g and 2.0-20.0 mg/100 g, respectively. Based on the results of this work, it can be concluded that chlorogenic acid can increase the safety, shelf life, and quality of fishery products.

Consumer Perception of Freshness and Volatile Composition of Fresh Gilthead Seabream and Seabass in Active Packaging with and without CO2-Emitting Pads

Active packaging with CO₂-emitters (pads) has recently been used for shelf-life extension of fresh fish. The aim of this study was to identify consumer attitudes towards fresh fish packaging, to examine whether Greek consumers prefer active packaging with pad over active packaging without pad, to investigate any perceived differences in the sensory freshness of the fish, and to relate consumer perception to volatile composition of fish fillets. In total, 274 consumers participated in the study which included freshness sensory evaluation of gilthead seabream (Sparus aurata) and seabass (Dicentrarchuslabrax), whole-gutted and filleted, raw and cooked, at high quality and at the end of high-quality shelf-life. Samples were packed under modified atmosphere either with a pad or without. Results showed that consumers preferred packages with pads, especially at the end of high quality shelf-life. They perceived raw samples packed with a pad to be fresher and closer to the ideal product, and also had a higher purchase intention towards them. Cooked samples were not perceived differently. Consumers' perception was in accordance with the GC-MS findings in the volatile compounds that function as freshness or spoilage indicators. Most participants were positive towards fresh fish packaging although they usually buy unpacked fresh fish. Our results suggest that active packaging with CO₂ emitters contribute to freshness preservation and that it has a positive potential in the Greek market.

Raw and Cooked Quality of Gilthead Seabream Fillets (Sparus aurata, L.) after Mild Processing via Osmotic Dehydration for Shelf Life Extension

The current study aimed to explore the effects of mild processing for shelf-life extension on the raw an-d cooked quality of gilthead seabream fillets stored at 2 °C. Control and Treated (via osmotic dehydration) fillets were sampled at the beginning (D1), middle (D5) and end (D7) of commercial shelf life. The raw quality was evaluated via the quality index method (QIM), microbial measurements and for D1 through tetrad discrimination testing. The cooked quality was evaluated for the same samples via sensory descriptive analyses with a trained panel. The tetrad results indicated similar characteristics between treatments for raw fillets on D1 and a 29% shelf-life extension for Treated fillets vs. the Control ones, defined by Quality Index Method and microbial measurements. The raw quality was reflected in the cooked quality of the tissue, with the Treated fillets exhibiting less intense spoilage-related sensory attributes as well as enhanced or retained freshness-related attributes throughout storage, when compared to the Control ones. A range of treatment induced sensory characteristics, partly associated to Maillard reactions, were developed in the Treated fillets. Overall, the treatment affected positively both the raw and cooked quality of the fillet, showing promising results as a shelf-life extension method for fish fillet preservation.

Quality Boost and Shelf-Life Prolongation of African Catfish Fillet Using Lepidium sativum Mucilage Extract and Selenium Nanoparticles

Aiming to boost the catfish fillet quality, the consequences of their treatment with Lepidium sativum seeds mucilage (LSSM) and with LSSM-mediated selenium nanoparticles (LSSM-Se NPs) were investigated. The LSSM assessment for phenolic acids contents emphasized higher concentrations. Green-synthesized Se NPs were conjugated with LSSM to form LSSM-Se NPs and characterized; the NPs had spherical shapes, negatively charged with 15.47 nm mean diameters. Fish fillets were immersed in coating solutions for 2 min, drained, and stored for 25 days at 4°C. The fish groups (C: untreated samples, M: LSSM-treated, and G: LSSM-Se NPs treated) were assessed for their physicochemical, bacteriological, and sensorial attributes. On the 25th day, the samples’ pH values were 6.96, 6.6, and 6.3; TVB-N values were 38.8, 28.4, and 16.4 mg/100 g; TBARS values were 1.7, 0.97, and 0.68 malondialdehyde/kg; and overall acceptability scores were 3.9, 5.6, and 8.3, for C, M and G groups, respectively. At day 16, the psychrophilic bacterial count was 6.2, 4.0, and 3.6 log CFU/g for C, M, and G groups, respectively. The application of LSSM and LSSM-Se NPs is recommended to compose active coatings for quality boost and shelf-life extension of stored catfish fillet.

Determining spoilage of whiteleg shrimp (Litopanaeus vannemei) during refrigerated storage using colorimetric strips

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Colorimetric strips were found to be applicable to determine the spoilage level of the commonly consumed crustacean (shrimp).

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The strips are relatively easy to use and offer a cost-efficient alternative to sensory and laborious laboratory methodology for seafood quality assessment.

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Strip results aligned well with the current sensory seafood grading system used by FDA/NOAA for inspection and possibly could serve as a replacement for sensory analysis.

A reliable spoilage assessment method is needed to ensure sufficient quality control of shrimp. Colorimetric dye-based indicators that change color in response to pH changes can monitor food quality changes in a simple, quick, and accurate way and generate easy-to-interpret results. Significant positive correlations with storage time were observed for the results of the bromophenol blue (BPB) strips (r = 0.8513, p < 0.0001) and the rose bengal strips (r = 0.8981, p < 0.0001). The results of both colorimetric methods significantly correlated with sensory and chemical quality indicators, including sensory attributes “salty water-like”, “natto water-like” and “sour milk-like”, and volatile compounds such as 3-methyl-3-butenol, 2-methyl-1-butanol, 3-methyl-1-butanol, hexanol, 2-methyl-1-butanal, and 3-methyl-1-butanal. The BPB strips and rose bengal strips have the potential to be used as objective, accurate, and cost-efficient methods to evaluate shrimp quality and lead to consistent and easy-to-interpret results.

Exploring the Dynamic of Bacterial Communities in Manila Clam (Ruditapes philippinarum) During Refrigerated Storage

Microorganism contamination is one of the most important factors affecting the spoilage and food safety of Manila clams. This study aimed to gain insights into bacterial composition and the dynamic change of bacterial communities on retailed Manila clam during refrigerated storage within the edible period. High-throughput sequencing was conducted to monitor the bacterial population with the prolongation of storage time of Day 0, Day 1, and Day 3. Result demonstrated that phyla of Proteobacteria, Actinobacteriota, Acidobacteriota, and Chloroflexi composed the majority of bacterial communities during the whole observation process. Furthermore, the increase of Proteobacteria showed a positive correlation with the storage time, whereas Acidobacteriota and Chloroflexi continued to decline in storage. For genus annotation, none of genus obtained dominant population in storage. From Day 0 to Day 1, the genera of Streptomyces, Bradyrhizobium, and Mycobacterium significantly increased; meanwhile, 12 genera significantly decreased. Compared with samples at Day 0, a total of 15 genera significantly decreased with the reduced proportion ranging from 0.50 to 4.40% at Day 3. At the end of the storage, the genus Crossiella became the most redundant population. Both the richness and diversity decreased at the start of storage at Day 1, and then slightly increased at Day 3 was observed. Based on the result in this study, strategy targeting the increased bacteria could be tested to improve the consumption quality and safety of refrigerated clam.

Rapid quality deterioration of harpiosquillid mantis shrimp (Harpiosquilla raphidea) during iced storage

Changes in physicochemical, textural, microbial, and sensory quality of harpiosquillid mantis shrimp (Harpiosquilla raphidea) (HMS) during 10 days of iced storage were studied. Weight and cooking losses were increased during storage (p < 0.05). Drastic decrease in myosin heavy chain was found after 2 days of storage. Increases in total volatile basic nitrogen, trimethylamine, peroxide value, and thiobarbituric acid reactive substances with coincidentally augmented pH were found during the storage (p < 0.05). For microbiological analyses, total viable counts exceeded the limit at day 6. Melanosis score increased with a decreased L* value as storage time increased. Rapid decreases in hardness, springiness, cohesiveness, gumminess, and chewiness were associated with pasty and softened texture, which was supported by looser arrangement of muscle fiber along with gapping. This was reconfirmed by lowered shear force. Based on the quality evaluation, HMS could maintain the freshness and quality for not longer than 2 days in ice.

Safety and Quality of Canned Sardines after Opening: A Shelf-Stability Study

This study aimed to define the shelf life of canned sardines after opening to increase consumer awareness of their quality and safety and reduce food waste. For this purpose, canned sardines (Sardina pilchardus) packed with different sauces were opened and stored at 4 °C for 7 days. Microbiological, sensorial, physical and chemical stability was monitored daily by standard methodologies. Results show that the overall quality and safety are highly dependent on the sauce type. To preserve their full quality, sardines in brine and in vegetable oil should be consumed up to 1 day after opening, while sardines in tomato sauce were stable for up to 3 days, although none were considered nonedible up to the 7th day. Many parameters demonstrated statistical differences and correlations with storage, although they were not as decisive as sensory evaluation. This integrated approach should be adopted by the food industry and regulating authorities to provide information to consumers regarding the quality and safety of handled goods.

Evaluation of the slow-release polylactic acid/polyhydroxyalkanoates active film containing oregano essential oil on the quality and flavor of chilled pufferfish (Takifugu obscurus) fillets

Active packaging is an innovative and effective way to extend the shelf life of food, but few studies have focused on the effect of its active ingredients on food flavor. This study aimed to develop slow-release polylactic acid/polyhydroxyalkanoates (PLA/PHA) active packaging containing oregano essential oil (OEO) and investigate the effect of active composite packaging on the flavor and quality of pufferfish fillets. The plasticizing effect of OEO increased the elongation at break (EAB) of the films from 23.36% to 65.80%. The adsorption of montmorillonite (MMT) reduces the loss of OEO during processing. The amount of active substance (carvacrol) released from PLA/PHA/OEO/MMT film to pufferfish was 9.70 mg/kg. The pufferfish fillets packed in PLA/PHA/OEO/MMT film showed the slightest difference on the 8th day from the beginning of storage. The slow-release composite films could extend the shelf life of pufferfish fillets by 2-3 days at 4 °C ± 1 °C.

Assessment of quality attributes of porcine blood and liver hydrolysates incorporated pork loaves stored under aerobic and modified atmospheric packaging

Lipid oxidation and microbial proliferations were studied in pork loaves prepared with incorporation of blood and liver protein hydrolysates stored in aerobic and MAP packaging for 28 and 42 days at 4 ± 1 ºC. In in-vitro trials selected levels i.e. blood hydrolysate (T1 and T3-600 mg/g), and liver hydrolysate (T2 and T4-600 mg/g), control without hydrolysate (C1-00 and C2-00 mg/g) w/w of emulsion, were added into pork loaves and packaged under aerobic (C1, T1 and T2) and MAP (C2, T3 and T4) condition. Physico-chemicals as pH, water activity_, titratable acidity, lipid-oxidations, color profile, textural indices, microbial qualities and sensorial properties were analyzed. Significant (p < 0.05) lower lipid oxidation, microbial proliferations and decrease in sensory attributes were seen for tested groups and MAP than aerobic packaging. It can be concluded that pork loaves containing porcine blood and liver hydrolysates can be successfully stored upto 28th days in aerobically packed and 42 days in MAP condition at refrigerated storage with acceptable physico-chemical, oxidative stability, microbiological and sensory quality. Whereas, pork loves prepared with blood hydrolysate (T3-600 mg/g), packaged under MAP condition were superior for all studied attributes than other groups. Blood and liver hydrolysate might be used as an alternative to synthetic preservative for meat preservation.

An Active Peptide-Based Packaging System to Improve the Freshness and Safety of Fish Products: A Case Study

Fresh fish are highly perishable, owing mainly to their moisture content, high amount of free amino acids and polyunsaturated fatty acids. Microorganisms and chemical reactions cause the spoilage, leading to loss in quality, human health risks and a market value reduction. Therefore, the fishing industry has always been willing to explore new technologies to increase quality and safety of fish products through a decrease of the microbiological and biochemical damage. In this context, antimicrobial active packaging is one such promising solution to meet consumer demands. The main objective of this study was to evaluate the effects of an active polypropylene-based packaging functionalized with the antimicrobial peptide 1018K6 on microbial growth, physicochemical properties and the sensory attributes of raw salmon fillets. The results showed that application of 1018K6-polypropylene strongly inhibited the microbial growth of both pathogenic and specific spoilage organisms (SSOs) on fish fillets after 7 days. Moreover, salmon also kept its freshness as per volatile chemical spoilage indices (CSIs) during storage. Similar results were obtained on hamburgers of Sarda sarda performing the same analyses. This work provides further evidence that 1018K6-polymers have good potential as antimicrobial packaging for application in the food market to enhance quality and preserve the sensorial properties of fish products.

Current freezing and thawing scenarios employed by North Atlantic fisheries: their potential role in Newfoundland and Labrador's northern cod (Gadus morhua) fishery

Seafood is very perishable and can quickly spoil due to three mechanisms: autolysis, microbial degradation, and oxidation. Primary commercial sectors within the North Atlantic fisheries include demersal, pelagic, and shellfish fisheries. The preservation techniques employed across each sector can be relatively consistent; however, some key differences exist across species and regions to maintain product freshness. Freezing has long been employed as a preservation technique to maintain product quality for extended periods. Freezing allows seafood to be held until demand improves and shipped long distances using lower-cost ground transportation while maintaining organoleptic properties and product quality. Thawing is the opposite of freezing and can be applied before additional processing or the final sale point. However, all preservation techniques have limitations, and a properly frozen and thawed fish will still suffer from drip loss. This review summarizes the general introduction of spoilage and seafood spoilage mechanisms and the latest preservation techniques in the seafood industry, focusing on freezing and thawing processes and technologies. This review also considers the concept of global value chains (GVC) and the points to freeze and thaw seafood along the GVC to improve its quality with the intention of helping Newfoundland and Labrador’s emerging Northern cod (Gadus morhua) fisheries enhance product quality, meet market demands and increase stakeholder value.

Mild processing of seafood-A review

Recent years have shown a tremendous increase in consumer demands for healthy, natural, high-quality convenience foods, especially within the fish and seafood sector. Traditional processing technologies such as drying or extensive heating can cause deterioration of nutrients and sensory quality uncompilable with these demands. This has led to development of many novel processing technologies, which include several mild technologies. The present review highlights the potential of mild thermal, and nonthermal physical, and chemical technologies, either used alone or in combination, to obtain safe seafood products with good shelf life and preference among consumers. Moreover, applications and limitations are discussed to provide a clear view of the potential for future development and applications. Some of the reviewed technologies, or combinations thereof, have shown great potential for non-seafood products, yet data are missing for fish and seafood in general. The present paper visualizes these knowledge gaps and the potential for new technology developments in the seafood sector. Among identified gaps, the combination of mild heating (e.g., sous vide or microwave) with more novel technologies such as pulsed electric field, pulsed light, soluble gas stabilization, cold plasma, or Ohmic heat must be highlighted. However, before industrial applications are available, more research is needed.

Bimetallic Au@Pt Nanocrystal Sensitization Mesoporous α-Fe2O3 Hollow Nanocubes for Highly Sensitive and Rapid Detection of Fish Freshness at Low Temperature

In this work, we present a new metal oxide semiconductor gas sensor for detecting trimethylamine (TMA) by bimetal Au@Pt-modified α-Fe₂O₃ hollow nanocubes (NCs) as sensing materials. The structure and morphological characteristics of Au@Pt/α-Fe₂O₃ were evaluated through multiple analyses, and their gas-sensitive performance was investigated. Compared with the pristine α-Fe₂O₃ NC sensor, the sensor based on Au@Pt/α-Fe₂O₃ NCs exhibited faster response time (5 s) and higher response (R_a/R_g = 32) toward 100 ppm TMA gas at a lower temperature (150 °C). Furthermore, we also assessed the Au@Pt/α-Fe₂O₃ NC sensor for detecting the freshness of Larimichthys crocea which have been observed by headspace solid-phase microextraction and gas chromatography-mass spectrometry. The high performance of the Au@Pt/α-Fe₂O₃ NCs is attributed to the special hollow morphology with a high specific surface area (212.9 m²/g) and the synergistic effect of the Au@Pt bimetal. The Au@Pt/α-Fe₂O₃ sensor shows promising application prospects in estimating seafood freshness on the spot.

Employment of Flake Ice Systems Including Natural Preservative Compounds for the Quality Enhancement of Chilled Seafood-A Review

Marine species deteriorate rapidly post-mortem as a consequence of a variety of biochemical and microbial breakdown mechanisms. Due to the increasing demand for high-quality fresh seafood, different strategies are now available to retard spoilage for as long as possible. The present study provides an overview of a recently proposed strategy based on the addition of natural compounds to marine species. In this strategy, different kinds of natural preservative compounds are included in the flake-ice medium that is commonly used for chilled storage. Natural sources tested for this purpose include low-molecular-weight organic acids and different kinds of extracts of plants, macroalgae, and by-products resulting from marine species commercialization. The preservative action of such treatments is analyzed according to the effect on different deteriorative mechanisms (i.e., lipid hydrolysis, oxidation, and microbial activity development), as well as on the resulting sensory acceptability and shelf-life time. The basic objective of this review is to provide an overview concerning the positive effect that the presence in an icing system of natural preserving compounds may have on the quality of chilled marine species. Furthermore, various potential avenues are proposed to develop the practical and commercial employment of this technological strategy.

Effect of High-Pressure Processing on Physico-Chemical, Microbiological and Sensory Traits in Fresh Fish Fillets (Salmo salar and Pleuronectes platessa)

High-pressure (HP) treatment could lead to several advantages when applied to fish and seafood since it would affect the extension of the shelf life of this highly perishable food. In this regard, this study aimed to evaluate the effect of high-pressure treatment (500 MPa for 2 min at a temperature of 4 °C) on changes in quality on two different kinds of fresh fish fillets (Salmo salar and Pleuronectes platessa). Specifically, physico-chemical (VOCs, untargeted metabolomics spectra, pH and color), microbiological (Enterobacteriaceae, Pseudomonas spp., mesophilic and psychrotrophic bacteria) and sensory traits were evaluated at different days of refrigerated storage. From the results obtained, it is possible to state that the high pressure significantly (p ≤ 0.05) reduced microbial growth for each investigated microorganism. Regarding the colorimetric coordinates, no remarkable effects on a* and b* indices were found, while a significant effect (p = 0.01) was observed on the colorimetric index L*, making the HP-treated samples lighter than their respective controls. The sensory analysis showed that for the odor attribute, the HP treatment seems to have had a stabilizing action during shelf-life. Moreover, the treated samples obtained a better score than the respective controls (p ≤ 0.05). With regards to texture and appearance attributes, the treatment seems to have had a significant (p ≤ 0.05) effect, making the treated samples more compact and opaque than controls, therefore resulting in the loss of the characteristics of raw fish for the treated samples. Moreover, from a chemical point of view, HP treatment prevents the development of volatile sulfides and delays the formation of histamine (p ≤ 0.05). Very interestingly, the metabolomic approach revealed novel dipeptide markers for the HP procedure.

From Farm to Fingers: an Exploration of Probiotics for Oysters, from Production to Human Consumption

Oysters hold a unique place within the field of aquaculture as one of the only organisms that is regularly shipped live to be consumed whole and raw. The microbiota of oysters is capable of adapting to a wide range of environmental conditions within their dynamic estuarine environments; however, human aquaculture practices can challenge the resilience of this microbial community. Several discrete stages in oyster cultivation and market processing can cause disruption to the oyster microbiota, thus increasing the possibility of proliferation by pathogens and spoilage bacteria. These same pressure points offer the opportunity for the application of probiotics to help decrease disease occurrence in stocks, improve product yields, minimize the risk of shellfish poisoning, and increase product shelf life. This review provides a summary of the current knowledge on oyster microbiota, the impact of aquaculture upon this community, and the current status of oyster probiotic development. In response to this biotechnological gap, the authors highlight opportunities of highest potential impact within the aquaculture pipeline and propose a strategy for oyster-specific probiotic candidate development.

Establishment of a Model for Evaluating Shelf Life of Pseudosciaena crocea in Simulated Logistics and Storage

ABSTRACT

Cold chain logistics is a common way of fresh-keeping transportation at present, but in the actual transportation and storage process, temperature control is often not accurate, which leads to shortened shelf life. We evaluated the changes in the quality of yellow croaker (Pseudosciaena crocea) at different temperatures during transportation. Specimens of P. crocea were immersed in slurry ice for 20 min and stored at 22, 4, or -1°C for 4 days. During this period, the development of rancidity of P. crocea was measured by sensory (odor, skin, color, and flesh appearance) and biochemical (total number of colonies, total volatile basic nitrogen, and K value) analyses. A combination of sensory and biochemical parameters and the Arrhenius equation were used to predict the shelf life of P. crocea during storage. After verification under different storage temperatures, the relative error between the predicted and the measured values was found to be within 15%. The present work provides theoretical guidance for the quality control of P. crocea during transportation and storage.

HIGHLIGHTS

Development of a rapid colorimetric strip method for determination of volatile bases in mahi-mahi and tuna

Tuna (Thunnus albacares) and mahi-mahi (Coryphaena hippurus) are two major fish species responsible for scombroid poisoning in the United States. The purpose of this research was to develop a low-cost and easily operated colorimetric strip method for the rapid determination of spoilage degree via amine response in mahi-mahi and tuna. The color strip method was developed by investigating different types of dyes, filter papers, sample volume, water bath temperature, and other parameters. Ultimately rose bengal and bromophenol blue (BPB) dyes were chosen. These two dyes produced standard curves with good linearity (0-50 mg/L for the total biogenic amines) and uniformity of color change. The r² values for the standard curves of the rose Bengal and BPB were 0.9535 and 0.8883, respectively. Significant positive Pearson correlations coefficients (r) between the volatile biogenic amine levels detected by these two colorimetric strip methods with increasing spoilage grade of mahi-mahi (rose bengal: r = 0.8907, p < 0.0001; BPB: r = 0.8711, p < 0.0001) and tuna (rose bengal: r = 0.8351, p < 0.0001; BPB: r = 0.7362, p = 0.0001) were observed. For mahi-mahi, the volatile amines detected by the colorimetric strips correlated positively with increasing levels of eight biogenic amines, free alanine, four aldehydes, isoamyl alcohol, two ketones, and dimethyl disulfide. For tuna, the results determined by colorimetric strips positively correlated with three biogenic amines, three free amino acids, four aldehydes, and ethanol. The two validated colorimetric strips could rapidly monitor the spoilage degree of mahi-mahi and tuna at low-cost. PRACTICAL APPLICATION: Rose bengal strips and BPB strips were developed as a rapid, objective, analytical method that can serve as an alternative to sensory grading methods. These two nonspecific colorimetric strip methods provided good linear response and uniformity of color change. Volatile amine levels in fish determined by these colorimetric strip methods were statistically significant and positively correlated with the spoilage grade of fish.

Recent Developments in Smart Food Packaging Focused on Biobased and Biodegradable Polymers

Food packaging has a crucial function in the modern food industry. New food packaging technologies seek to meet consumers and industrial's demands. Changes related to food production, sale practices and consumers' lifestyles, along with environmental awareness and the advance in new areas of knowledge (such as nanotechnology or biotechnology), act as driving forces to develop smart packages that can extend food shelf-life, keeping and supervising their innocuousness and quality and also taking care of the environment. This review describes the main concepts and types of active and intelligent food packaging, focusing on recent progress and new trends using biodegradable and biobased polymers. Numerous studies show the great possibilities of these materials. Future research needs to focus on some important aspects such as possibilities to scale-up, costs, regulatory aspects, and consumers' acceptance, to make these systems commercially viable.

Effect of Processing on Fish Protein Antigenicity and Allergenicity

Fish allergy is a life-long food allergy whose prevalence is affected by many demographic factors. Currently, there is no cure for fish allergy, which can only be managed by strict avoidance of fish in the diet. According to the WHO/IUIS Allergen Nomenclature Sub-Committee, 12 fish proteins are recognized as allergens. Different processing (thermal and non-thermal) techniques are applied to fish and fishery products to reduce microorganisms, extend shelf life, and alter organoleptic/nutritional properties. In this concise review, the development of a consistent terminology for studying food protein immunogenicity, antigenicity, and allergenicity is proposed. It also summarizes that food processing may lead to a decrease, no change, or even increase in fish antigenicity and allergenicity due to the change of protein solubility, protein denaturation, and the modification of linear or conformational epitopes. Recent studies investigated the effect of processing on fish antigenicity/allergenicity and were mainly conducted on commonly consumed fish species and major fish allergens using in vitro methods. Future research areas such as novel fish species/allergens and ex vivo/in vivo evaluation methods would convey a comprehensive view of the relationship between processing and fish allergy.

Effect of storage temperature and time on the fatty acids and nutritional quality of the commercial mussel (Mytilus galloprovincialis)

The effect of storage time (5, 10 and 15 days) and temperature (- 20 °C and + 4 °C) on the biochemical composition of the Tunisian mussel (Mytilus galloprovincialis) was evaluated by investigating changes in proximate composition, fatty acids, minerals and nutritional quality indices. Lipid and protein degradations were also evaluated through several markers of oxidative damage. Results showed a significant decrease in the biochemical compounds in mussel tissues after both refrigeration and freezing processes (p < 0.01). As regards the fatty acid composition, saturated fatty acids increased significantly after both storage processes. However, polyunsaturated and monounsaturated decreased, especially after 10 and 15 days of storage. The reduction of nutritional quality and mineral contents were detected after both storage processes. Markers of oxidative damage varied remarkably between fresh and stored tissues, revealing that both processes greatly influenced the nutritional quality of mussels. Overall, it is well recommended to consume fresh and stored mussels for no more than 5 days in the refrigerator (+ 4 °C) in order to preserve the better quality of this product and provide more benefits for human health.

Qualitative detection of formaldehyde and ammonia in fish and other seafoods obtained from Chennai's (India) fish markets

Illegal usage of formaldehyde and ammonia by fishermen and fish sellers for longer preservation of fish and other seafoods during sales and transportation has recently become a problem. Therefore, the present study was conducted to verify the presence or absence of formaldehyde and ammonia in fish and other seafoods that are commercially important for India, which are obtained from fish markets in Chennai. The present investigation results reveal contamination with formaldehyde and ammonia of commercially important fish and other seafoods collected from fish markets in Chennai. Formaldehyde was detected in 100% of samples in N4 Beach fish market, 93.33% of samples in Chintadripet fish market, 80.77% of samples in Vanagaram fish market, 68% of samples in Pattinapakkam fish market, and 58.33% of samples in Kasimedu fish market. Ammonia was detected in 100% of fish samples in N4 Beach, Chintadripet, Pattinapakkam, and Kasimedu fish market. Since formaldehyde and ammonia are harmful to human health, there is a need to develop a more suitable technology to extend the shelf life of the fish and other seafoods during transport and storage for longer preservation. Strict regulations should be made to control the usage of these harmful chemical substances.

Atomic force microscopy in food preservation research: New insights to overcome spoilage issues

A higher level of food safety is required due to the fast-growing human population along with the increased awareness of healthy lifestyles. Currently, a large percentage of food is spoiled during storage and processing due to enzymes and microbial activity, causing huge economic losses to both producers and consumers. Atomic force microscopy (AFM), as a powerful scanning probe microscopy, has been successfully and widely used in food preservation research. This technique allows a non-invasive examination of food products, providing high-resolution images of surface structure and individual polymers as well as the physical properties and adhesion of single molecules. In this paper, detailed applications of AFM in food preservation are reviewed. AFM has been used to provide comprehensive information in food preservation by evaluating the spoilage with its related structure modification. By utilizing AFM imaging and force measurement function, the main mechanisms involved in the loss of food quality and preservation technologies development can be further elucidated. It is also capable of exploring the activities of enzymes and microbes in influencing the quality of food products during storage. AFM provides comprehensive solutions to overcome spoilage issues with its versatile functions and high-throughput outcomes. Further research and development of this novel technique in order to solve integrated problems in food preservation are necessary.

Umai Dish Preparation Practices and Food Safety Behaviors in Bintulu Locals on Borneo Island, Malaysia

ABSTRACT

Umai is a popular, traditional, native dish of the Melanau ethnic group in Sarawak. It is prepared using thin slices of raw marine fish marinated with calamansi juice and seasoned with other ingredients. The local people believe that the acidity of the citrus juice, along with the use of salt and spice, can slightly cook the fish and remove the fishy smell. The aim of this study was to investigate (i) the different umai handling and preparation practices and (ii) the personal experience of umai consumption among respondents. A purposive sample of 100 umai makers, divided into two equal groups, professionals and nonprofessionals, participated in the study. We found that Spanish mackerel and hairfin anchovy were ranked first and second in the list of species chosen for making umai, with the former mostly preferred by the professional group, as opposed to the latter, which was preferred by the nonprofessional group. Black pomfret was ranked third, where it is equally preferred by both groups. About 20% of respondents would freeze the raw fish chunks prior to preparing umai, as opposed to 26% who would sun dry their fish. Other techniques, such as salting and marinating (using calamansi juice), were also used during the preparation of umai. Most of the respondents indicated that they would consider the umai ready to eat soon after marinating (with all ingredients) the raw fish. One-third of both respondent groups indicated that they would chill the umai dish at 4°C for 30 min before serving. The respondents could not provide any rationale behind these food preparation practices. Overall, this study provides evidence of the different preparation methods for umai. These practices can thus be considered important targets for public health education campaigns seeking to improve food safety surrounding this food group.

HIGHLIGHTS

Biomonitoring of Mercury, Cadmium and Selenium in Fish and the Population of Puerto Nariño, at the Southern Corner of the Colombian Amazon

Heavy metals threaten communities near biodiversity hotspots, as their protein sources come from the environment. This study assessed Hg, Cd, and Se concentrations in fish, as well as the magnitude of exposure and hematological conditions of adult citizens from Puerto Nariño (Colombian Amazon). Among fish samples, greater Hg concentrations were found in higher trophic level species, including Rhaphiodon vulpinus (880 ± 130 ng/g) and Pseudoplatystoma tigrinum (920 ± 87 ng/g). These species presented the highest hazard quotients and lowest Se:Hg molar ratios among those studied, showing their consumption represents a health risk to consumers. Moreover, some samples of Mylossoma duriventre and Prochilodus magdalenae had Cd levels greater than the regulated limit (100 ng/g). The average total Hg (T-Hg) concentrations in human hair and blood were 5.31 µg/g and 13.7 µg/L, respectively. All hair samples exceeded the 1.0 μg/g threshold set by the USEPA, whereas 93% of the volunteers had T-Hg blood levels greater than 5 μg/L, suggesting elevated exposure. The mean Cd level was 3.1 µg/L, with 21% of samples surpassing 5 µg/L, value at which mitigating actions should be taken. Eighty-four percent of participants presented Se deficiencies (<100 μg/L). There was a significant association between fish consumption and T-Hg in hair (ρ = 0.323; p = 0.032) and blood (ρ = 0.381; p = 0.011). In this last matrix, Se correlated with Cd content, whereas lymphocytes were inversely linked to Hg concentrations. The results of this study show that there is  extensive exposure to Hg in fish, the consumption of which may promote detrimental impacts on hematology parameters within the community.

Effect of Prior Chilling Period and Alga-Extract Packaging on the Quality of a Canned Underutilised Fish Species

The effect of a prior chilling period and an alga extract packaging on the quality of a canned underutilised mackerel species (Scomber colias) was investigated. For this different chilling times (0, 4 and 9 days) were taken into account and three concentrations of aqueous extracts of the macroalga Fucus spiralis were tested in a brine-packaging medium. Chemical changes related to quality were analysed after 3 months of canned storage. A substantial increase (p < 0.05) in free fatty acid content was observed in canned fish by increasing the chilling time; however, alga extract presence in the packaging medium led to decreased mean values. Concerning lipid oxidation development, an increased chilling time led to higher values (p < 0.05) of thiobarbituric acid index and fluorescent compounds formation; remarkably, an increased presence of alga extract led to a higher (p < 0.05) peroxide retention and lower (p < 0.05) fluorescent compounds content. Average colour L* and a* values showed a decrease and an increase, respectively, with chilling time; however, such changes were minimised with the alga extract content in the packaging system. Trimethylamine content revealed a marked increase as a result of the sterilisation step, but no influence (p > 0.05) of the chilling time or the alga-packaging medium could be implied.

Sanitary quality improvement of fish produced in the northern Benin cotton basin water reservoirs by cage culture and fish transfer in agricultural contaminant-free water: human health implications

Northern Benin water reservoirs may remain valuable resources for fish production if the ecotoxicological risks related to agricultural pesticides are eradicated. The present work was undertaken (i) to evaluate sanitary quality and human health implications of fish (Clarias gariepinus and Oreochromis niloticus) reared in cages compared with those produced in pens installed in a contaminated water reservoir (Batran) and a reference water reservoir (Songhaï) and (ii) to test the efficacy of fish transferring to water without agricultural contaminants on fish health status. Pathogenic bacteria and pesticide residues were analyzed by phenotypic and biochemical identification and gas chromatography coupled with mass spectrometry, respectively. For both species, Aeromonas species occur in fish reared in pens at Batran. In Batran, regardless of infrastructure and species, residues of 4,4'-DDE (Dichlorodiphenyldichloroethylene) (1.4-4.9 μg/kg) and Chlorpyriphos (ethyl) (2.8-12.1 μg/kg) were measured, while only the last molecule was found in C. gariepinus from Songhaï (8.9-8.10 μg/kg). Irrespective of the species in the Batran water reservoir, Chlorpyriphos (ethyl) concentration was higher in cages and lower in pens, while 4, 4'-DDE was more concentrated in fish farmed in pens. Levels of these pesticide residues were well below World Health Organization/Food and Agriculture Organization permissible limits and the risk analyzed indicates no potential adverse health implications in consumption of these fish. Also, fish bacteriological quality was in compliance with the international standards. The fish decontamination approach used herein results in a reduction of the splenic macrophage phagocytic activity in both studied fish species.